Search
Doubt
Call us on
Email us at
Menubar
ORCHIDS The International School

NCERT Solutions for Class 8 Science Chapter 17 – Stars and the Solar System

Orchid International School is delighted to offer free PDF downloads of NCERT Solutions for Class 8 Science Chapter 17. Once downloaded, these solutions become a readily available resource for students, even when they do not have internet connectivity. Our NCERT Solutions for Class 8 Science are meticulously prepared by our academic experts, who possess extensive knowledge of the academic field. These NCERT Solutions for Class 8 can be conveniently downloaded from our website and our app.

Access Answers to NCERT Solutions for Class 8 Science Chapter 17 – Stars and the Solar System

Stars and the Solar System

Question 1 :

Match items in column A with one or more items in column B.

A

B

Inner planets

Saturn

Outer planets 

Pole star

Constellation

Great Bear

Satellite of the Earth 

Moon

 

Earth

 

Orion

 

Mars

 

Answer :

 Inner planets are the first four planets closest to the Sun-Mercury, Venus, Earth, and Mars.

Therefore, (i) Inner planets – e) Earth, g) Mars

Outer planets are the last four planets closest to the Sun – Jupiter, Saturn, Uranus, and Neptune

Therefore, (ii) Outer planets – a) Saturn

A constellation is a group of stars forming a definite shape.

Therefore, (iii) Constellation – c) Great Bear, f) Orion

A satellite of the earth is the moon. 

Therefore, (iv) Satellite of earth – d) Moon

 


Question 2 :

In which part of the sky can you find Venus if it is visible as an evening star?

 

Answer :

 The part of the sky where we can find Venus if it is visible as an evening star is the west side of the sky.

 


Question 3 :

 Name the largest planet of the solar system.

 

Answer :

The largest planet of the solar system is Jupiter and the smallest planet is Mercury.

 


Question 4 :

What is a constellation? Name any two constellations.

 

Answer :

A constellation is a group of stars forming a definite shape. The two constellations are: 

i) Orion: It is located on the celestial equator and is visible throughout the world. It is a constellation in the night sky.

ii) Great Bear: It is located in the northern sky.

 


Question 5 :

 Which of the following is NOT a member of the solar system?

a) An asteroid

b) A satellite

c) A constellation

d) A comet

 

Answer :

(c) A constellation

A constellation is not a member of the solar system because it is a group of stars forming a definite shape whereas an asteroid, satellite, and comet are a part of the solar system.

 


Question 6 :

Draw sketches to show the relative position of prominent stars in

a) Ursa Major

b) Orion

 

Answer :

a) Ursa major is located in the northern sky. 

The sketch of the Ursa Major is:

Ursa Major

b)  Orion is located on the celestial equator and is visible throughout the world. It is a constellation in the night sky.

The sketch of the Orion is:

(Image Will Be Updated Soon)

 


Question 7 :

 Name two objects other than planets that are members of the solar system.

 

Answer :

The two other objects other than planets that are members of the solar system are:

i) Stars: Stars are celestial bodies made up of gases; they are huge in size and have very high temperatures

ii) Asteroid: Asteroids are small, rocky objects that orbit the sun.

 


Question 8 :

 Explain how you can locate the Pole Star with the help of Ursa Major.

 

Answer :

 We locate the Pole Star with the help of Ursa Major with the help of the three stars at the end of Ursa Major. To do so, create a straight line passing through the last three stars and extend that line in the north direction. The star seen in that direction is the Pole star.

Ursa Major

 


Question 9 :

Do all the stars in the sky move? Explain.

 

Answer :

No, the stars in the sky do not move because the Pole star is located above the axis of rotation of the Earth in the north direction. And hence it appears to be stationary and all other stars in the sky appear to move from East to West.

 


Question 10 :

 Which of the following is NOT a planet of the sun?

a) Sirius

b) Mercury

c) Saturn

d) Earth

 

Answer :

a) Sirius

Sirius is not a planet of the sun but a star. The planets of the sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

 


Question 11 :

Phases of the moon occur because

a) we can see only that part of the moon that reflects light towards us.

b) our distance from the moon keeps changing.

c) The shadow of the Earth covers only a part of the moon’s surface. 

d) The thickness of the moon’s atmosphere is not constant.

 

Answer :

 (a) we can see only that part of the moon that reflects light towards us.

Phases of the moon occur because the source of light of the moon is the Sun, it does not have its light and hence, it reflects the light coming from the sun and we can only see that part of the moon that reflects light towards us.

 


Question 12 :

Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light-years away from the Earth?

 

Answer :

 Stars are very far away from each other and the standard km notation of the distance seems unrealistic to use for denoting the distance between stars and hence, a much convenient and larger unit is used for expressing these distances which are known as light-years. It helps to make calculations and imagination easy.

One light-year denotes the distance traveled by light in one year.

1 Light Year = 9.46×

10

12

 km

1 Light Year = 9.46×1012 �� 

A star is eight light-years away from the Earth means that a star is

8× 9.46×

10

12

=7.568×

10

13

 km

8× 9.46×1012=7.568×1013 �� away from the Earth.

 


Question 13 :

The radius of Jupiter is 11 times the radius of the Earth. Calculate the ratio of the volumes of Jupiter and the Earth. How many Earths can Jupiter accommodate?

 

Answer :

The shape of Earth and Jupiter is a sphere. Let the radius of Earth be

R

E

�� and the radius of Jupiter be

R

J

��.

Given,

R

J

=11⋅

R

e

��=11⋅��    …..(1)

We know that the volume of a sphere of the radius

r

� is

4

3

π

r

3

43��3. Therefore, 

The volume of Earth,

V

E

=

4

3

π

R

3

E

��=43���3   …… (2)  

The volume of Jupiter,

V

J

=

4

3

π

R

3

J

��=43���3   

But from (1),

R

J

=11⋅

R

e

��=11⋅��. Hence, Volume of Jupiter,

V

J

=

(11)

3

4

3

π

R

3

E

��=(11)343���3  ...(3)

From (2) and (3), the ratio of the volumes of Jupiter and the Earth is

 

V

J

V

E

=

(11)

3

4

3

π

R

3

E

4

3

π

R

3

E

����=(11)343���343���3

V

J

V

E

=

(11)

3

⇒����=(11)3

V

J

V

E

=1331

∴����=1331

This means that Jupiter can accommodate

1331

1331 earth.

 


Question 14 :

Fill in the blanks:

a) The planet which is farthest from the sun is _________.

b) The planet which appears reddish in colour is _________.

c) A group of stars that appear to form a pattern in the sky is known as a _________.

d) A celestial body that revolves around a planet is known as a _______.

e) Shooting stars are actually not _________.

f) Asteroids are found between the orbits of ____ and _____.

 

Answer :

a) The planet which is farthest from the sun is Neptune.

b) The planet which appears reddish in color is Mars.

c) A group of stars that appear to form a pattern in the sky is known as a Constellation. 

d)  A celestial body that revolves around a planet is known as a satellite.

e) Shooting stars are actually not stars. 

f)  Asteroids are found between the orbits of Mars and Jupiter.

 


Question 15 :

Mark the following statement as true (T) or false (F).

a) Pole star is a member of the solar system. 

b) Mercury is the smallest planet in the solar system. 

c) Uranus is the farthest planet in the solar system. 

d) INSAT is an artificial satellite.

e) There are nine planets in the solar system. 

f) Constellation Orion can be seen only with a telescope.

 

Answer :

a) True

Stars are a member of the solar system.

b) True

Mercury is the smallest planet and all other planets are larger than mercury.

c) False

Neptune is the farthest planet in the solar system. 

d) True

INSAT is a man-made satellite.

e) False

There are eight planets in the solar system. The planets of the sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

f) False

During winters, the constellation Orion is visible with naked eyes.

 


Question 16 :

Boojho made the following sketch of the solar system. Is the sketch correct? If not, correct it.

Solar System

 

Answer :

The figure of the solar system is incorrect because 

a) The positions of Mars and Venus are interchanged.

b) The positions of Uranus and Neptune are interchanged.

c) The asteroid belt which is between Mars and Jupiter should be present between Jupiter and Saturn.

The correct figure is:

 

 

https://cdn-cms.orchidsinternationalschool.com/media/answer/ncert-class-8-science-chapter-17-stars-and-the-solar-system.png

Enquire Now

Copyright @2024 | K12 Techno Services ®

ORCHIDS - The International School | Terms | Privacy Policy | Cancellation